Make a boolean in the server called IsGW
Code:
public static bool IsGW = false;
Then do something like
Code:
Timer GWTimer = new Timer(60000); // Call the check every 60 seconds
GWTimer.Elapsed += delegate { if (!IsGW && DateTime.Now.DayOfWeek == DayOfWeek.Saturday) { IsGW = true; /* Your GW code here */ };
GWTimer.Start();
GC.KeepAlive(GWTimer);
Prolly better ways, but you get the idea.